The ISS was crewed by the first three Expedition 30 crewmembers for approximately five-and-a-half weeks. They were joined on 23 December 2011 by the Expedition 30/31 crew,[8] who were carried to the ISS by the Soyuz TMA-03M spacecraft. Soyuz TMA-03M was launched on 21 December 2011 at 13:16 UTC[9] and docked on 23 December at 15:19 UTC.[10]

On 21 December 2011, Expedition 30 commander Dan Burbank observed a pass of the comet C/2011 W3 Lovejoy. The comet was initially thought to be in a destructive orbit around the sun, and passed within 140,000 km (87,000 mi) of the sun's surface.[11] However, the comet ultimately survived its encounter with the sun.

On 16 February 2012, Russian crew members Oleg Kononenko and Anton Shkaplerov performed the first spacewalk of 2012, moving one of the station's Strela cranes from the Pirs module to the Poisk module. The astronauts also installed new debris shields and materials experiments on the exterior of the ISS.[12]

The European Space Agency's third Automated Transfer Vehicle (ATV), Edoardo Amaldi, was launched on 23 March 2012, and docked successfully with the ISS on 28 March.[14] The robotic ATV carried around 6,595 kilograms (14,539 lb) of propellants, water and dry cargo to the Expedition 30 crew, and also helped boost the station's altitude with its thrusters.[15] The ATV ultimately remained docked until September 2012, whereafter it deorbited and burned up in Earth's atmosphere as planned.[16]

Progress M-15M, a Russian unmanned resupply spacecraft, was launched to the ISS from Baikonur Cosmodrome on 20 April 2012. It successfully docked with the station on 22 April.[17] In preparation for the spacecraft's arrival, its predecessor, Progress M-14M, undocked from the ISS on 19 April, having been docked since 28 January.[18]

Expedition 30 ended on 27 April 2012 with the departure of Soyuz TMA-22 from the ISS, carrying astronauts Burbank, Shkaplerov and Ivanishin. The three astronauts landed safely in Kazakhstan at 11:45 AM (GMT), while Kononenko, Kuipers and Pettit remained aboard the station to begin Expedition 31.[2]